Qt 5.13 was released on June 19th https://blog.qt.io/blog/2019/06/19/qt-5-13-released/
Plasma 5.17 is scheduled for 10th October https://community.kde.org/Schedules/Plasma_5 We have yet to decide which version of Qt we will say Plasma 5.17 works with. If nobody has a reason to need Qt 5.13 I will set it to say it works with both Qt 5.12 and 5.13. Jonathan